Bath unit for use by invalids

ABSTRACT

This invention relates to a bath unit for use by, for example, invalids and includes a hollow buoyant platform mounted in the bath receptacle for constrained upright movement relative thereto with the platform being maintained in a substantially horizontal position when stationary or during upright movement. The upright movement of the platform relative to the bath receptacle when filled with water is achieved by controlling an inflow or outflow of bath water into or out of the platform. At the upper limit of upright movement, the top surface of the platform is substantially level with the top edges of the bath receptacle; however, since the platform is prevented from further upward movement by arresting means, the upward force of bath water, displaced by the platform, on the empty buoyant platform enables the platform to receive a body of an invalid thereon without causing the platform to move downward until the upward force of bath water has been removed by the inflowing of the bath water into the platform.

United States Patent [191 Adamson BATH UNIT FOR USE BY INVALIDS [76] Inventor: William George Adamson, 14,

Kilkeel Rd., Annalong, Newry, Northern Ireland [22] Filed: May 17, 1972 [21] Appl. No.: 254,152

[52] US. Cl. 4/185 L, 114/48 [51] Int. Cl A47k 3/12 [58] Field of Search 4/185 L, 185 R, 185 B, 4/185 AB, 185 HB, 185 S, 173; 114/48 [56] References Cited UNITED STATES PATENTS 2,604,638 7/1952 Furry 4/185 L 2,643,662 6/1953 Bunce 4/185 L 3,346,885 10/1967 Merriman 4/185 L 1,683,430 9/1928 Wright 4/185 L FOREIGN PATENTS OR APPLICATIONS 66,092 12/1892 Germany 4/185 AB 386,404 1/1933 Great Britain 4/185 L 719,244 12/1954 Great Britain 4/185 L 705,811 3/1954 Great Britain 4/185 R Apr. 9, 1974 Primary ExaminerLeon G. Machlin Attorney, Agent, or Firm-Young & Thompson 57 ABSTRACT This invention relates to a bath unit for use by, for example, invalids and includes a hollow buoyant platform mounted in the bath receptacle for constrained upright movement relative thereto with the platform being maintained in a substantially horizontal position when stationary or during upright movement. The upright movement of the platform relative to the bath receptacle when filled with water is achieved by controlling an inflow or outflow of bath water into or out of the platform. At the upper limit of upright movement, the top surface of the platform is substantially level with the top edges of the bath receptacle; however, since the platform is prevented from further upward movement by arresting means, the upward force of bath water, displaced by the platform, on the empty buoyant platform enables the platform to receive a body of an invalid thereon without causing the platform to move downward until the upward force of bath water has been removed by the inflowing of the bath water into the platform.

5 Claims, 9 Drawing Figures BATH UNIT FOR USE BY INVALIDS This invention relates to a bath unit of a type that may be used by, for example, invalids, geriatric persons, or physically handicapped or disabled persons for the total or partial immersion of the human body (hereinafter in the specification and claims referred to as the body) in liquid, located in the bath receptacle, for hygenic, therapeutic, pre-or post-surgical, cosmetic or other similar purposes.

The present invention is a bath unit in which a platform is mounted in the bath receptacle for constrained upright movement relative thereto, the platform being adapted to be maintained in a substantially horizontal position when stationary or during upright movement. The platform may be at least partially hollow and buoyant in liquid, and upright movement of the platform with liquid in the bath receptacle may be achieved by controlling the inflow or outflow of liquid ballast into or out of the hollow in the platform.

Preferably, the liquid ballast is liquid taken from the liquid in the bath receptacle. The amount of liquid ballast used may be substantially equal to the amount of liquid in the bath receptacle which is displaced by the platform and body being partially or wholly immersed in the liquid.

Preferably also, the platform is provided with one or more tanks which can each be filled with air to assist in the buoyancy of the platform or can be filled with liquid ballast.

Preferably further, arresting means are provided to limit the amount of upward movement of the platform, when in use, relative to the bath receptacle, the arresting means being removable or displacable to allow the platform to be lifted out of the bath receptacle to permit cleaning of the platform and of the bath receptacle and for maintenance purposes.

An embodiment of the present invention will now'be described by way of example with reference to the accompanying drawings in which,

FIG. 1 is a diagrammatic perspective view of a bath unit according to the present invention,

FIG. 2 is a diagrammatic side elevation of the bath unit,

FIG. 3 is a diagrammatic end view of the bath unit,

FIG. 4A is a plan view of one embodiment of upright constraints used in the bath unit between a bath receptacle and a platform,

FIG. 4B is an end view of FIG. 4A,

FIG. 4C is a side elevation of FIG. 4B, and

FIG. 5 is a plan view of a second embodiment of upright constraints.

In FIGS. 1, 2 and 3 the denotion (a) indicates that the platform is in an upper position and denotion (b) indicates that the platform is in a lower position.

Referring to the drawings, a bath unit has a rectangular platform mounted in the bath receptacle 12 for constrained vertical movement relative thereto between an upper position in which the top of the platform 10 is level with the top of the bath receptacle 12 which position is controlled by arresting means to be described hereinafter and a lower position i.e., at A" in which the platform 10 rests on or on upward extensions of the base of the bath receptacle. The bath receptacle 12 is rectangular with vertical side and end walls each having a curved outwardly extending lip.

This constrained movement is achieved (FIG. 4) by having vertical constraints comprising two first channel members 1 1 located, transversely'spaced apart, at each end of the platform 10 and each member 11 mating, and being in sliding engagement, with a corresponding positioned second channel member 13 mounted uprightly on the end walls of thebath receptacle 12. Each first channel member 11 is provided with two vertically spaced spindles 14 each extending between the limbs of the channel member 11 and carrying, for free rotational movement, a pair of transversely spaced pulley wheels 15. The outer edges of the limbs of the second channel members 13 engage the respective grooves of the pulley wheels 15. The outer edges of said limbs of the channel members 13, or the grooves of the pulley wheels 15, or both, may be coated with a material having a low coefficient of friction, for example, poly-tetra-fluoroethylene (P.T.F.E.). The flanges of the pulley wheels 15 prevent lateral movement of the platform. The platform 10 is prevented from tipping longitudinally by wheels 15 being vertically displaced.

Arresting means is provided in each vertical constraint to limit the upward movement of the platform 10 relative to the bath receptacle 12 and is constituted by a plate 16 being located extending inwardly of the bath receptacle 12 from the web of each second channel member 13, said'plate 16 being engagable by a plate 26 provided at the lower end of each first channel member 11 and extending outwardly from the platform 10. The plates 16 are each removable or displacable by conventional means to allow the platform 10 to be removed from the bath receptacle 12 to permit cleaning of the platform 10 and of the bath receptacle l2 and for maintenance purposes.

The platform 10 is of buoyant material and is provided with an internal tank (not shown). The platform 10 is adapted as hereinafter described to support its own weight plus a body weight of approximately twenty stone when it is arrested in the upper position and the bath receptacle 12 is full of liquid. The platform 10 has a first nozzle 17 communicating with the tank and projecting from its base which can act as an inlet or as an outlet, this first nozzle 17 being connected by a flexible tube 18 to a second nozzle 19 connected to one of two passages 27 of an electrically operable reversible pump 20, the second passage 28 being connected to a third nozzle 29 communicating with the interior of the bath receptacle 12. The pump 20 serves to pump liquid in the bath receptacle l2 therefrom and into the tank in the platform 10 to provide liquid ballast, or to pump liquid from the tank back into the bath receptacle 12 to enable the platform 10 to float upward under its own buoyancy. The amount of liquid pumped into the tank of the platform 10 as ballast to enable the platform 10 to become submerged is found to be substantially equal to the amount of liquid which is displaced, according to the Law of Flotation, by the submersion of the platform 10. A rigid pipe 30 is mounted upstanding inside the platform 10 with its upper end terminating short of the inside surface of the top thereof. The lower end of the pipe 30 communicates with an orifice 31 provided in the base of the platform 10 which itself is connected by a flexible pipe 32 to a nozzle 33 provided in the end wall of the bath receptacle [2. This serves to retain the pressure in the tank of the platform 10 at atmospheric pressure at all times, the level of the top of the pipe 30 being at all times above the level of any liquid ballast therein.

A set of three taps (not shown) are provided on the outside or on the top of the lip of one side wall of the bath receptacle 12 to remotely control the flow of liquid into or out of the bath receptacle 12 and the inflow or outflow of liquid into or out of the tank of the plat form 10. One of the taps is provided for the inflow of liquid into the bath receptacle and is associated with a thermostatically controlled mixer valve 21 for controlling the relative amounts of hot and cold liquid to be mixed prior to inflowing into the bath receptacle 12 through an inlet 22 located in an end wall of the bath receptacle 12. A second tap controls remotely the outflow of liquid from the bath receptacle 12 through outlet 23. The third tap has three positions and these positions are designated on a plate (not shown) surrounding the third tap. The positions are down" standing for inflow of liquid into the tank from the liquid in the bath receptacle 12, "off" standing for a neutral position and "up standing for outflow of liquid from the tank. When the third tap is moved to the down or up positions it actuates the pump to outflow or inflow liquid from the bath receptacle 12 into or out of the tank respectively.

A contoured back rest 24 is provided for adjustable mounting on the platform 10 to support the back of a body.

Initially, in use the bath receptacle l2 and platform 10 are empty with the platform 10 in its lower position. The first tap is turned on a desired amount and the bath receptacle 12 filled up to a predetermined level with liquid, for example water, at the selected temperature. The platform 10 rises with rise in liquid into the bath receptacle 12. After the arresting means operate to prevent further upward movement of the platform 10, liquid continues to rise around the platform 10 until the level of liquid reaches the level of an overflow orifice 25 in the side of the bath receptacle 12. The liquid displaced around the platform 10 exerts an upward thrust of approximately 20 stone weight on the platform 10 and accordingly there will be no downward movement of the platform 10 unless a body of in excess of twenty stone weight is laid thereon. By turning the third tap to the down position, liquid from the bath receptacle 12 is inflowed, as liquid ballast, into the tank and the platform 10 slowly sinks into the liquid. If necessary the third tap can be moved to the off position before the tank of the platform 10 is fully filled, if desired, otherwise, it is only moved to the off position after the platform 10 has reached its lowest position at A in the bath receptacle 12. The liquid inflowed into the tank to cause the platform to submerge causes a corresponding decrease in the amount of liquid in the bath receptacle which compensates substantially for the displacement of liquid by the whole or partial submersion of the platform 10 and body. After the purpose for which the body has been immersed has been completed, the third tap is turned to the up position and the liquid ballast is pumped out of the tank thereby allowing the platform 10 to rise under its buoyancy pr0perties until it is again held rigidly by the arresting means in its upper position. When the weight of the body is removed from the platform 10 the second tap is turned on to allow the liquid in the bath receptacle 12 to drain away through outlet 23. As the liquid leave the bath receptacle 12, so the platform 10 moves down with its level to finally rest in its lower position and all the liquid is drained away under gravity.

EXAMPLE In a bath receptacle having internal measurements approximately 5 feet 6 inches long and 1 foot 9 inches wide, a platform of rectangular shape would require to be approximately 6 inches deep to obtain an upward thrust of 20 stone weight when the platform 10 is in its upper position and the bath receptacle 12 is full of liquid. The immediate effect of the pumping action of the pump 20 when the third tap is turned to the down" position will be to reduce the level of liquid in the bath receptacle 12 by 6 inches thus preventing any overflow of liquid due to liquid displacement by whole or partial immersion of the body. Since the quantity of liquid initially pumped is small depending on clearance between the platform 10 and bath receptacle 12 this reduction in liquid level will occur before there is any downward movement of the platform 10. With the distance between the lowest level of the platform 10 and the top of the bath receptacle l2 taken as 18 inches, then when the platform 10 is in its lowest position it will contain 6 inches of liquid leaving 6 inches ofliquid plus the liquid displaced by the body, i.e., approximately 8 9 inches of liquid in all in which to perform the bathing operation.

Provision can be made without departing from the scope of the present invention to allow the liquid ballast in the platform to be drained away under gravity therefrom should there be a pump failure.

Each movement of the raising or lowering of the platform 10 can be terminated automatically. The pumping action to ballast the platform can be cut-off by a time switch since the performance of the pump 20 and the quantity of liquid to be pumped are constant and the time can be predetermined. The operation of emptying the platform 10 can be terminated by a vacuum switch associated with the pump 10 to cut-off the pump.

The bottom of the bath receptacle 12 can be contoured to accommodate the tube 18 and flexible pipe 32 in their folded position, i.e., when the platform 10 is in its lowest position, to achieve an optimum shape to allow all the liquid to drain therefrom to waste, and to support the platform 10 in its lowest position. The volume of space left between level A and the bottom of the bath receptacle 12 should be as small as possible. A waterproof hinged door can be located in the side of the receptacle to give easy and quick access to pipe or tube connections and for cleaning purposes.

In a modification, only one vertical constraint may be provided at each end, or alternatively the vertical constraints (FIG. 5) may comprise vertical rectangular recesses 35 in the end walls of the bath receptacle l2 and vertical rectangular projections 36 extending from the end walls of the platform 10.

The top of the platform 10 which supports the main part of the body may be contoured to body shape.

Castors may be mounted on the base of the bath receptacle 12 to allow the bath unit to be wheeled about from position to position i.e., from bedside to bedside of a ward in a hospital, provision being made for filling and emptying the bath receptacle with liquid from take-off taps provided for such use.

Stabilising means may be provided, if found necessary, to hold the platform in a horizontal position when stationary or during vertical movement. These means may comprise one or more vertical ribs provided on each longitudinal side of the platform and each being engaged in a corresponding vertical slot provided in the respective side wall of the bath receptacle 12. Two one-way electrically operable pumps may be substituted without departing from the scope of the invention, in the place of, and to perform the functions of, the electrically operable reversible pump.

I claim:

1. A bath unit including a bath receptacle adapted to receive a liquid, a platform mounted in the bath receptacle for supporting a body at least part of which platform is hollow, pump means for the passage of liquid from the bath receptacle into the hollow part of the platform and vice versa to control flotation and submersion of the platform in the receptacle said pump means comprising a pump and conduit means connecting said pump with said hollow part of the platform, means for controlling said pump whereby the platform can be wholly submerged below or raised to float on the surface of the liquid in the bath and means for constraining movement of the platform in a vertical plane, said means comprising co-operating guide members on the bath receptacle and platform located on opposed faces thereof.

2. A bath unit according to claim 1, wherein a rigid pipe is mounted upstanding inside the platform with its upper end terminating short of the inside surface of the top of the platform the lower end of said pipe communicating with atmosphere via a flexible pipe connected to a nozzle in a wall of the bath unit.

3. A bath unit according to claim 1, wherein said constraining means comprises a pair of opposed channels mounted at each end of the bath unit each pair of channels being arranged such that one pair carries a spindle mounting pulley wheels thereon the other pair engaging the grooves of respective pulley wheels.

4. A bath unit according to claim 1, wherein said constraining means comprises a pair of co-operating channel and rail members mounted at each end of the bath unit.

5. A bath unit according to claim 1, wherein a stabilising means is provided to hold the platform in a horizontal position, said means comprising one or more vertical ribs engageable with corresponding vertical slots provided in the platform and bath receptacle respectively. 

1. A bath unit including a bath receptacle adapted to receive a liquid, a platform mounted in the bath receptacle for supporting a body at least part of which platform is hollow, pump means for the passage of liquid from the bath receptacle into the hollow part of the platform and vice versa to control flotation and submersion of the platform in the receptacle said pump means comprising a pump and conduit means connecting said pump with said hollow part of the platform, means for controlling said pump whereby the platform can be wholly submerged below or raised to float on the surface of the liquid in the bath and means for constraining movement of the platform in a vertical plane, said means comprising co-operating guide members on the bath receptacle and platform located on opposed faces thereof.
 2. A bath unit according to claim 1, wherein a rigid pipe is mounted upstanding inside the platform with its upper end terminating short of the inside surface of the top of the platform the lower end of said pipe communicating with atmosphere via a flexible pipe connected to a nozzle in a wall of the bath unit.
 3. A bath unit according to claim 1, wherein said constraining means comprises a pair of opposed channels mounted at each end of the bath unit each pair of channels being arranged such that one pair carries a spindle mounting pulley wheels thereon the other pair engaging the grooves of respective pulley wheels.
 4. A bath unit according to claim 1, wherein said constraining means comprises a pair of co-operating channel and rail members mounted at each end of the bath unit.
 5. A bath unit according to claim 1, wherein a stabilising means is provided to hold the platform in a horizontal position, said means comprising one or more vertical ribs engageable with corresponding vertical slots provided in the platform and bath receptacle respectively. 